This invention relates generally to dynamoelectric machines and, more particularly, to methods for manufacturing a lubrication system for such machines having new and improved bearing lubrication systems.
In rotating dynamoelectric machines, e.g., motors, generators, and alternators; a rotatable member is supported by one or more bearing devices for rotation relative to a stationary member. Such bearing devices or systems may be, for example, of the rolling bearing type (e.g., ball bearings) or of the journal bearing type (e.g., sleeve bearings). Although the principles of the invention described herein may be used to advantage with either of these types of systems, the detailed description will proceed with particular reference to dynamoelectric machines of the sleeve bearing type and the invention will be discussed in connection with embodiments illustrated as fractional horsepower sleeve bearing machines.
It will be understood that, for satisfactory operation over long periods of time (e.g., for a number of years), means must be provided that will maintain an adequate supply and flow of lubricant to a sleeve bearing.
Common approaches heretofore have included the provision of lubricant storage and feeding means that store a supply of lubricating material, such as oil, and that provide a supply of oil for a bearing during motor operation. After the oil has moved along bearing surfaces during operation, the oil has then recirculated to the lubricant reservoir. For many years, lubricant reservoir cavities have been designed to accommodate materials such as felt. This felt absorbs and thus stores oil that could later be wicked or fed to a bearing during motor operation. More recently, materials have been developed which may be injected or otherwise very quickly disposed in a lubricant reservoir cavity adjacent to a motor bearing, and such materials then also are relied upon (with or without felt feed wicks) to feed oil to the motor bearing during operation. One of the materials that has been used heretofore is described for example in M. L. Abel U.S. Pat. No. 3,434,765 and the same type of material is referred to in Ridgway U.S. Pat. No. 3,184,272.
The particular material mentioned in the Abel and Ridgway patents is marketed under the name "PERMAWICK" by the Permawick Company of Detroit, Mich. Other approaches utilize the type of lubricating material or materials of the type described either in Staak U.S. Pat. No. 2,979,779 or James Whitt's applications Ser. Nos. 292,664 and 292,550 (both now abandoned); both of which were titled "Extrudable Lubricant" and were assigned to the assignee of this application. The use of any of these types of materials may contribute to reduced labor costs associated with manufacturing motors, but problems have been encountered due to the difference in the physical nature and characteristics between felt materials and extrudable lubricant materials.
For example, there is a tendency for extrudable materials to flow into portions of lubricant defining reservoirs other than those selected to be filled with such material; whereas pieces of felt tend to stay where they have been placed. In addition, much care must be taken to ensure that extrudable materials do not obstruct or interfere with oil recirculating means such as oil slingers. Even when this has been done, however, the tire required to fill a reservoir with extrudable lubricant has been relatively long because only one, or at most two, extrusion ports have been used during filling of such reservoirs. Accordingly, it would be desirable to provide dynamoelectric machines having a new and improved lubrication system, and mehtods to be used when making or manufacturing the same that would overcome problems mentioned above as well as other problems that will become more apparent from the following disclosure.